Common sense started life as Aristotle's name for a sixth sense
For Aristotle, the 'common sense' was an inner faculty that fused sight, sound and smell into perception of one real thing. Romans turned it into tact and community feeling. Only in the early 1700s did English give it today's meaning of obvious truths, and Thomas Paine then used it to help spark revolutions.
Today the phrase means judgment and knowledge shared by nearly everyone, held without argument or reflection. It carries a double edge. Since the Enlightenment it has been praised as the source of good taste and the axioms of science, and dismissed as conventional wisdom, prejudice and superstition. The concept draws on at least two older philosophical meanings, one about perception and one about shared humanity, and their interplay is especially marked in English, whose term has since gone international.
Aristotle's koine aisthesis was a central faculty of the soul, shared with animals, that combined inputs from the separate senses. Heller-Roazen notes that medieval Arabic and Latin thinkers, from Al-Farabi and Avicenna to Thomas Aquinas, assembled a whole doctrine from scattered remarks in Aristotle's writings on the soul, making it one of his most durable ideas. Stoic terms added further layers; Marcus Aurelius used a related word in listing what he learned from his adoptive father.
Roman writers bent the idea toward social life. Cicero warned orators that straying from everyday language and the community's sense was the cardinal sin of their craft. Quintilian argued a boy should go to school rather than be tutored at home, since otherwise he could never absorb this shared sense, and in Horace the bore who talks at someone plainly unwilling to listen is said to lack it. C. S. Lewis observed that at its lowest level the Roman usage simply meant tact, close to the ideal of humanitas.
The modern sense crystallised in the early eighteenth century, partly in reaction to Descartes, who opened his Discourse on Method by saying everyone has enough good sense but rarely uses it well, so a sceptical method was needed. Enlightenment empiricists instead embraced common sense against metaphysics associated with the old regime. Paine's 1776 pamphlet Common Sense has been called the century's most influential political pamphlet, shaping both the American and French revolutions.
Source: Common sense
